Igniting means for burners



pria w, 1946. D. BEGGS 27,398,611

Y IGNITING MEANS. FOR BURNERS l Filed April-1, 1941 v Z Smaentor Qqgy@wim Gttorneg Patented Apr. 16, 1946 UNITED STATE.

s Partitur oFFice IGNITING MEANS ron. BURNERS Don Beggs, Toledo, Ohio,assignor, by mesne` assignments, to Surface Combustion Corporation,Toledo, Ohio, a corporation of Ohio Application April 1, 1941, SerialNo. 386,236 i 7 Claims. (Cl. 126-91) This invention relates toimprovements in heating apparatus of the type wherein fuel gas andcombustion-supported air are delivered to a combustion chamber inseparate but contiguous streams in order to obtain delayed combustion.One example of such apparatus is shown in patent to Hepburn et al., No.2,047,471, wherein the combustion chamber is atube adapted to be used asa heating element; in furnace chambers and the like. It will also benoted that in this patent the means for igniting the gas comprises apremix burner around the discharge end of the fuel supnomenon in thefollowing way: Referring to Figs. 2 and 3, IS indicates a relativelysmall baille in the form of `a radially extending'iinger at one end of arod Il positioned in the air passage I5, the linger being relativelyclose to the discharge end of the gas discharge tube I4. Due to the zoneof reduced pressure at the downstream side ply tube. The object of thepresent invention is to provide a simple and practical improvement inmeans for providing a pilot flame for a firing system of the typedisclosed in said patent. Other objects will appear as the descriptionproceeds.

-In the accompanying drawing wherein the preferred form of the inventionis disclosed- Fig. 1 illustrates the type of heating apparatus withwhich the invention has special utility; namely, heating apparatus,embodying an internally 'red tube for use as a heating element infurnace chambers and the like.

A Fig. 7 is a cross sectionA on line 'I-l of Fig. 6,l for the purpose ofillustrating the application of the modification shown in Fig. 4.

In Fig. 1, Iindicates a furnace chamber wall and I I a heating tubewhich extends into and out of said chamber through said Wall. At one endof said tube is a suction producing device I2 for producing draftthrough the tube.` Projecting into the other end of the tube to a pointsome distance inwardly from the air intake end' I3 thereof is a fuelsupply tube or conduit I4, it

being understood that the air. for supporting combustion of the fuelenters the tube I I through the annular flow passage I5 about the gassupply conduit.

The present invention is predicated on the phenomenon that a zone ofreduced pressure or partial vacuum tends to occur at the down streamside' of a non-streamline body placed in the path of ow of a stream ofair or other gas, In the present invention I take advantage of this phe-65 tion Wall for delivering separate streams 0i'.y fuel of this iingeror baille I6 some of the gas flowing 'from the tube I4 will tend to flowtoward the' zone of reduced pressure and in so doing will become mixedwith the air.` This mixture on heiligl ignited will form a pilot flameat the `end of the Y fuel tube I4 in igniting proximity Vto the Pointwhere the main air and gas streams meet as will now be readilyunderstood.

Other relatively small bailles I8 may extend rafdially outward from thetube I4 itself to provide a plurality of pilot flames around the tube.The primary reason for utilizing a rod I1 for sup# porting the baille I6is to permit the latter to be utilized as a spark electrode for ignitingthe mixture produced therebehind as said-it being` 1inderstood that therod I'I is connected to a suitable source of electric power (not shown)..It'

will also be understood that once the air-gas mixtures behind thebailies I6 and I 8 have been ignited the resulting pilot flames willtend to persist Vas long as both air and fuel gas flow into the radiatortube I I.

In Fig. 4, the arrangement is the .same as in Fig. 2 except that I'provide a relatively small gas port I9 in the wall' of the gas tube atthe downstream side of the baille I8 for the more direct flow of the gasfrom the tube to the zone of reduced pressure.

In Figs. 5 and?, I have shown how the inven tion may be applied to amodified form of burner adapted to fire into a furnace 2I| such as aforgefurnace. The gas passage is indicated at 2I and the air passage at22, the two passages being separated by a partition wall 23. The primednumerals indicate parts similar to those indicated by the same butnon-primed numerals in the other figures and the mode of operation willbe readily understood from what has already been said.

From the foregoing description it can bereadyily seen that the presentinvention provides a gas and air to a combustion space. of means forturbulently intermixing relatively small quantities of said streams toproduce a premix pilot name at the end of said wall. said meanscomprising a relatively small baffle positioned in the air passage tocause a turbulent partial vacuum to be produced thereinbehind thebaille, said baille being positioned in such close proximity tube havingat its exhaust end a suction producing device sothatcombustion-supporting air and fuel gas introduced into the tube atthe front tothe end of said wall that the said partial vacuum will beeffective to divert towards itself from a spark gap therebetween forigniting the airgas mixture produced as said. l

2. Th'e combination with an air passage and a gas passage separated fromeach other by a partition`wal1 for delivering separate streams of airand fuel gas to a combustion space, of means for producing a premixpilot flame in relatively close proximity to the downstream terminal ofysaid wall for igniting the air and gas issuing from said passages, saidmeans comprising a relatively small baiile in one of said passages inrelatively close proximity to the downstream terminal of said wall forproducing adjacent said terminal a turbulent partial vacuum to producethe air-gas mixture that maintains saidpremix ame, said baiile beingspaced from said wall to provide a spark gap therebetween for ignitingsaid mixture.

-end thereof will tend to Vbe drawn through the tube, a gas conductingtube projecting 4centrally into the front end of the combustion tube todischarge fuel gas centrally thereinto and to form vbetween the tubes anannular .passage for the inicoming air, and means for producing withinthe combustion tube a premix pilot flame forigniting the fuel gasissuing from the said gas conducting tube, said means comprising aradially extending finger in the air passage in relatively closeproximity to the discharge end of said gas conducting tube to producebehind the nger a turbulent partial vacuum eiectiveto divert towardsitself from the stream of gas from the gas conducting tube enough gas toproduce behind the finger a zone of combustible mixture sumcient tomaintain 'said pilot name at said zone.

6.`In combination, a relatively long combustion tube having at itsexhaust end a suction producing device so that combustion-supporting airand 3. The combination with an air passage and a l gas passage separatedfrom each other by a parti- I tion wall for delivering separate streamsof air and fuel gas to a combustion space, of means for producing. apremix pilot ame in relatively close proximity to the downstream`terminal of said wall for igniting the air and gas issuing from saidpassages, said means comprising a relatively small baille in the airpassage in relatively close proximity to the downstream terminal of saidwall for producing adjacent said terminal a tur l 5 bulent partia'l1vacuum which will be effective to divert towards itself from th'e maingas stream enoughy gas to produce the air-gas mixture that maintainssaid pilot flame, said wall being apertured in relatively closeproximity to said baille l at the downstream side of the latter for theflow of gas through said wall.

4. In combination, a relatively long combustion tube which at its intakeend has an air entering passage and a gas entering passage separatedfrom each other by a. partition wall so that'the air and gas willinitially enter the tube as separate straight away streams and which'tube at its exhaust endhas a suction devicefor producing a draft throughthetube, and means for producing a premix pilotlame in the tubeforigniting the gas where it first comes in contact with air after leavingthe gas passage comprising `a relatively small baille in the air passagein rela# tively close proximity to the downstream terminal of said wallfor producing behind said baille a turbulent partial vacuum effective todivert towards itself from the main gas .stream enough gas to producethe air-gas mixture that maintains said pilot flame.

v5. In combination, "a relatively long combustion fuel gas introducedinto the tube at the front end thereof will tend to be drawn through thetube, a. gas conducting tube projecting centrally into the front end ofthe combustion tube to discharge fuel gas centrallythereinto and tovformbetween the tubes an annular passage for the incoming air, and means forproducing within the combustion tube a premix pilot ilame for ignitingthe. fuel gas issuing from Athe said gas conducting tube, said meanscomprising a radially extending finger in the air passage in relativelyclose proximity to the discharge end of said gas conducting. tube toproduce behind the finger a turbulent partial vacuum effective to diverttowards itself from the stream of gas from the gas conducting tubeenough' gas to produce behind the finger a zone of combustible mixturesuflicient to main-` tain said pilot flame at said zone, the said fingerbeing radially spaced from the gas conducting tube to form a spark gaptherebetween for igniting said mixture.-

7. In combination, a relatively long combustion tube having at itsexhaust end a suction producing device so that combustion-supporting airand fuel gas introduced into the tube at the front. end thereof willtend to be drawn through the tube, a gas conducting tube projectingcentrally into the front end of the combustion tube to discharge fuelgas centrally thereinto and to form between the tubes an annular passagefor the incoming air, and means for producing within the combustion tubea plurality of premix pilot names each l adapted to ignite the fuel gasissuing from the gas conducting tube, said means comprising a.circumferential row of radially-extending ngers in the air passage inrelatively close proximity to the discharge en d of the gas conductingtube to -ing tube enough gas to form behind euch nger a zone ofcombustible mixture sufcient to maintain a pilot iiame at said zone.

f DON Bacuis.

